What is Beta-Sarcoglycanopathy?
Beta-sarcoglycanopathy, also known as limb-girdle muscular dystrophy type 2E (LGMD2E), typically causes muscle weakness as a result of a deficiency of the protein, beta-sarcoglycan, in the dystrophin-glycoprotein complex, a component of the muscle system. Symptoms of the disease vary greatly from person to person, even among people in the same family. Some people with the disease can have a mild course where they are nearly asymptomatic, while others may have severe symptoms that can be fatal.
People with beta-sarcoglycanopathy develop symptoms at variable ages, though symptoms tend to first present in childhood. Beta-sarcoglycanopathy does not affect intelligence or mental function; the most common symptom is progressive muscle weakness of the hip, shoulder, and abdomen (proximal muscles). The rate at which the muscles weaken can vary, but many experience progressive weakness to a point where a wheelchair becomes necessary. Other possible features include enlarged calf muscles (calf hypertrophy), contractures, scapular winging (shoulder blade is prominent), and scoliosis. Respiratory complications (~10-30% of individuals) or heart complications (~60-70% of individuals) are also associated with the sarcoglycanopathies, and may be a cause of death.
How common is Beta-Sarcoglycanopathy?
There are numerous types of limb-girdle muscular dystrophy. The estimated prevalence of all types of limb-girdle muscular dystrophy is 1 in 15,000 individuals. Beta-sarcoglycanopathy is rare and its exact incidence is unknown.
How is Beta-Sarcoglycanopathy treated?
There is no cure for beta-sarcoglycanopathy and few effective treatments. Physical therapy is often recommended to retain muscle strength and mobility for as long as possible. Stretching, mechanical aids, or surgery may aid in that goal. As muscles deteriorate, a ventilator may be required to aid breathing. Cardiac surveillance is recommended, and those who develop heart problems should consult with a cardiologist for symptomatic treatments.
What is the prognosis for a person with Beta-Sarcoglycanopathy?
The outlook for a person with beta-sarcoglycanopathy varies. Generally speaking, the earlier symptoms begin, the faster they progress. However, because symptoms and onset can be variable, prognosis can be variable. People with more severe symptoms can become wheelchair bound in their early teens and die in early adulthood with death usually being due to respiratory and/or cardiac complications.